Study of online fault diagnosis for distributed substation based on Petri nets

According to the distributed substation protection configuration and the principle of fault-clearance, a new model of fault diagnosis based on Petri net is proposed in this paper. In Petri net diagnosis model, all kinds of fault have a specific token which make it easily and clearly to find the fault location and understand the sequence of the fault events. The diagnostic is implemented by solving some matrix equations, which has a fast computational speed and a definite diagnostic result. The approach proposed is particular suitable for substation fault online diagnosis. Specially, in this model, the differential protection of the transformer and the bus bars are concerned as well as over current protection.